British police have identified Salman Abedi, 22, as the bomber behind the attack on an Ariana Grande concert Monday in Manchester, England. Abedi died in the bombing, which claimed the lives of at least 22 victims and injured dozens more — many of whom were children.

"Clearly, this was a pretty sophisticated and powerful bomb," a high-ranking Western government official told NPR, explaining that officers believe Abedi received help with the attack. "Our assessment is he did not have the skills to build such a bomb, and the conclusion is there is a bomb-maker out there."

Greater Manchester Police say Abedi — a British national whose father, Ramadan, comes from Libya — was part of a wider terror network.

His family has come under scrutiny, as well: Libya's RADA counterterrorism force issued a statement on Facebook saying it has arrested and interrogated Abedi's younger brother, Hashim. In the statement, the force says that the 20-year-old engineering student had been planning to launch an attack of his own in Tripoli and that after his arrest Tuesday night, Hashim confessed to ties with the Islamic State and knowledge of his brother's alleged plans for the Manchester attack.

The Associated Press reports the brothers' father, Ramadan Abedi, was also arrested in Libya but did not say why. In an interview with the AP before his arrest, Ramadan Abedi said his 23-year-old son, Ismail, had been arrested Tuesday, as well.

"We don't believe in killing innocents. This is not us," Ramadan Abedi told the news service. "We aren't the ones who blow up ourselves among innocents. We go to mosques. We recite Quran, but not that."

Ramadan Abedi fled to the U.K. in the early 1990s to escape the regime of Libyan dictator Moammar Gadhafi, according to The Guardian. The British newspaper reports that in 2001, he returned briefly to the country, where he fought Gadhafi's soldiers as part of the al-Qaida-linked Libyan Islamic Fighting group.

A Libyan neighbor says the elder Abedi returned again to Libya in 2011 after Gadhafi's government fell.

Salman Abedi lived for years with family in a modest red-brick house in the Fallowfield section of Manchester, a middle- to working-class neighborhood. Though his neighbors tell NPR they did not know him well, some of them recall an incident in which a resident complained to police several years ago that members of the Abedi family had shown signs of radicalization.

Police had followed up on the complaint at the time and visited the house.

The senior Western official tells NPR that Salman Abedi had returned from a trip to Libya in the past several days.